Design compromises in control systems for automatic operation of HF radio systems

In the past, experienced radio operators have been needed for satisfactory operation of HF skywave radio links, because of the continuously changing ionospheric conditions and interference. The challenge has fascinated radio amateurs for decades. Eliminating the human operator to make systems operate automatically and reliably is difficult. The paper discusses some of the design compromises involved in the design of automatic adaptive HF radio systems. All the building blocks are now available: remotely controlled transmitters, receivers and modems, and small low-cost computers for control. What is required are control procedures which are flexible and can cover every possible eventuality